#!@BASH_SHELL@
#
# Copyright (C) 2021 Red Hat, Inc.  All rights reserved.
#
# Authors: Christine Caulfield <ccaulfie@redhat.com>
#          Fabio M. Di Nitto <fdinitto@redhat.com>
#
# This program is free software; you can redistribute it and/or modify
# it under the terms of version 2 of the GNU General Public License as
# published by the Free Software Foundation.
#
# This program is distributed in the hope that it would be useful, but
# WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
#
# Further, this software is distributed without any warranty that it is
# free of the rightful claim of any third person regarding infringement
# or the like.  Any license provided herein, whether implied or
# otherwise, applies only to this software file.  Patent licenses, if
# any, provided herein do not apply to combinations of this program with
# other software, or any other product whatsoever.
#
# You should have received a copy of the GNU General Public License
# along with this program; if not, write the Free Software Foundation,
# Inc., 59 Temple Place - Suite 330, Boston MA 02111-1307, USA.
#

#
# Checks storage I/O status of all given drives and writes the #health-storage
# status into the CIB
# Implementation is heavily based on ocf:pacemaker:HealtSMART
#
# It sends a single block on IO to a radom location on the device and reports any errors returned.
# If the IO hangs, that will also be returned. (bear in mind tha tmay also hang the C app in some
# instances).
#
# It's worth making a note in the RA description that the smartmon RA is also recommended (this
# does not replace it), and that Pacemaker health checking should be configued.
#
# https://clusterlabs.org/pacemaker/doc/2.1/Pacemaker_Explained/singlehtml/index.html#tracking-node-health

#######################################################################

#######################################################################
# Initialization:

: ${OCF_FUNCTIONS_DIR=${OCF_ROOT}/lib/heartbeat}
. ${OCF_FUNCTIONS_DIR}/ocf-shellfuncs

#
STORAGEMON=$HA_BIN/storage_mon
ATTRDUP=/usr/sbin/attrd_updater

OCF_RESKEY_CRM_meta_interval_default="0"
OCF_RESKEY_io_timeout_default="10"
OCF_RESKEY_inject_errors_default=""
OCF_RESKEY_state_file_default="${HA_RSCTMP%%/}/storage-mon-${OCF_RESOURCE_INSTANCE}.state"

# Explicitly list all environment variables used, to make static analysis happy
: ${OCF_RESKEY_CRM_meta_interval:=${OCF_RESKEY_CRM_meta_interval_default}}
: ${OCF_RESKEY_drives:=""}
: ${OCF_RESKEY_io_timeout:=${OCF_RESKEY_io_timeout_default}}
: ${OCF_RESKEY_inject_errors:=${OCF_RESKEY_inject_errors_default}}
: ${OCF_RESKEY_state_file:=${OCF_RESKEY_state_file_default}}

#######################################################################

meta_data() {
	cat <<END
<?xml version="1.0"?>
<!DOCTYPE resource-agent SYSTEM "ra-api-1.dtd">
<resource-agent name="storage-mon" version="1.0">
<version>1.0</version>

<longdesc lang="en">
System health agent that checks the storage I/O status of the given drives and
updates the #health-storage attribute. Usage is highly recommended in combination
with the HealthSMART monitoring agent. The agent currently support a maximum of 25
devices per instance.
</longdesc>
<shortdesc lang="en">storage I/O health status</shortdesc>

<parameters>

<parameter name="state_file" unique="1">
<longdesc lang="en">
Location to store the resource state in.
</longdesc>
<shortdesc lang="en">State file</shortdesc>
<content type="string" default="${OCF_RESKEY_state_file_default}" />
</parameter>

<parameter name="drives" unique="1" required="1">
<longdesc lang="en">
The drive(s) to check as a SPACE separated list. Enter the full path to the device, e.g. "/dev/sda".
</longdesc>
<shortdesc lang="en">Drives to check</shortdesc>
<content type="string" default="" />
</parameter>

<parameter name="io_timeout" unique="0">
<longdesc lang="en">
Specify disk I/O timeout in seconds. Minimum 1, recommended 10 (default).
</longdesc>
<shortdesc lang="en">Disk I/O timeout</shortdesc>
<content type="integer" default="${OCF_RESKEY_io_timeout_default}" />
</parameter>

<parameter name="inject_errors" unique="0">
<longdesc lang="en">
Used only for testing! Specify % of I/O errors to simulate drives failures.
</longdesc>
<shortdesc lang="en">Specify % of I/O errors to simulate drives failures</shortdesc>
<content type="integer" default="${OCF_RESKEY_inject_errors_default}" />
</parameter>

</parameters>

<actions>
<action name="start"        timeout="10s" />
<action name="stop"         timeout="120s" />
<action name="monitor"      timeout="120s" interval="30s" start-delay="0s" />
<action name="meta-data"    timeout="5s" />
<action name="validate-all" timeout="10s" />
</actions>
</resource-agent>
END
	return $OCF_SUCCESS
}

#######################################################################

storage-mon_usage() {
	cat <<END
usage: $0 {start|stop|monitor|validate-all|meta-data}

Expects to have a fully populated OCF RA-compliant environment set.
END
	return $1
}

storage-mon_init() {
	#Test for presence of storage_mon helper
	if [ ! -x "$STORAGEMON" ] ; then
		ocf_log err "${STORAGEMON} not installed."
		exit $OCF_ERR_INSTALLED
	fi

	i=0
	for DRIVE in ${OCF_RESKEY_drives}; do
		if [ ! -e "$DRIVE" ] ; then
			ocf_log err "${DRIVE} not found on the system"
			exit $OCF_ERR_INSTALLED
		fi
		i=$((i + 1))
	done

	if [ "$i" -gt "25" ]; then
		ocf_log err "Too many drives ($i) configured for this agent. Max 25."
		exit $OCF_ERR_CONFIGURED
	fi

	if [ "${OCF_RESKEY_io_timeout}" -lt "1" ]; then
		ocf_log err "Minimum timeout is 1. Recommended 10 (default)."
		exit $OCF_ERR_CONFIGURED
	fi

	if [ -n "${OCF_RESKEY_inject_errors}" ]; then
		if [ "${OCF_RESKEY_inject_errors}" -lt "1" ] || [ "${OCF_RESKEY_inject_errors}" -gt "100" ]; then
			ocf_log err "Inject errors % has to be a value between 1 and 100."
			exit $OCF_ERR_CONFIGURED
		fi
	fi
}

storage-mon_validate() {
	storage-mon_init

	# Is the state directory writable?
	state_dir=$(dirname "$OCF_RESKEY_state_file")
	touch "$state_dir/$$"
	if [ $? -ne 0 ]; then
		return $OCF_ERR_CONFIGURED
	fi
	rm "$state_dir/$$"

	return $OCF_SUCCESS
}

storage-mon_monitor() {
	storage-mon_init

	# Monitor _MUST!_ differentiate correctly between running
	# (SUCCESS), failed (ERROR) or _cleanly_ stopped (NOT RUNNING).
	# That is THREE states, not just yes/no.

	if [ ! -f "${OCF_RESKEY_state_file}" ]; then
		return $OCF_NOT_RUNNING
	fi

	# generate command line
	cmdline=""
	for DRIVE in ${OCF_RESKEY_drives}; do
		cmdline="$cmdline --device $DRIVE --score 1"
	done
	cmdline="$cmdline --timeout ${OCF_RESKEY_io_timeout}"
	if [ -n "${OCF_RESKEY_inject_errors}" ]; then
		cmdline="$cmdline --inject-errors-percent ${OCF_RESKEY_inject_errors}"
	fi
	$STORAGEMON $cmdline
	if [ $? -ne 0 ]; then
		status="red"
	else
		status="green"
	fi

	"$ATTRDUP" -n "#health-${OCF_RESOURCE_INSTANCE}" -U "$status" -d "5s"
	return $OCF_SUCCESS
}

storage-mon_start() {
	storage-mon_monitor
	if [ $? -eq $OCF_SUCCESS ]; then
		return $OCF_SUCCESS
	fi
	touch "${OCF_RESKEY_state_file}"
}

storage-mon_stop() {
	storage-mon_monitor
	if [ $? -eq $OCF_SUCCESS ]; then
		rm "${OCF_RESKEY_state_file}"
	fi
	return $OCF_SUCCESS
}

storage-mon_validate() {
	storage-mon_init

	# Is the state directory writable?
	state_dir=$(dirname "${OCF_RESKEY_state_file}")
	touch "$state_dir/$$"
	if [ $? -ne 0 ]; then
		return $OCF_ERR_CONFIGURED
	fi
	rm "$state_dir/$$"

	return $OCF_SUCCESS
}

case "$__OCF_ACTION" in
	start)		storage-mon_start;;
	stop)		storage-mon_stop;;
	monitor)	storage-mon_monitor;;
	validate-all)	storage-mon_validate;;
	meta-data)	meta_data;;
	usage|help)	storage-mon_usage $OCF_SUCCESS;;
	*)		storage-mon_usage $OCF_ERR_UNIMPLEMENTED;;
esac
rc=$?
ocf_log debug "${OCF_RESOURCE_INSTANCE} $__OCF_ACTION : $rc"
exit $rc
# vim: set filetype=sh:
